The Stovebolt Site Forums The Shop Area Engine Shop the ole '49 gmc rearend swap

I am putting a small block in my 49 GMC longbed. My current torque tube rear is 56" between drum backing plates so I am using this number as the basis for replacement. I was told to look for an s-10 4x4 rear as they are the same width. The problem is that every rear is short. what I am finding is that 2 wheelers are 48" and 4x4's measure 53" which I am scared will not clear the frame rails. Does anyone know what years s-10 would be 56" or can suggest any other rears to look for.
Thanks, vik

There's a whole page on this in the tech tips section:
http://50chevy.freeservers.com/Suspension_Widths.html#Suspension

If your S-10 has 2" wide brakes, this puts the wheel flanges at about 57", which is going to be too narrow.

I have a '66 Chevy pickup axle that has 58" between drums, 62" between flanges. It has a 3.07 gear ratio and six lug bolt pattern. That is my #1 suggestion for interchangability. Its slightly wide but not noticable, about 1/2" per side according to my measurements on my Chevy. The spring perches have to be changed, though, the 66 is out of a coil spring truck.

Whoever told you the S-10 is the right width doesn't have the whole story and may have mislead you.

Do you want the five lug pattern or the six? Since the S-10 is five I'll guess that is the direction you want to do. I used the rear from a '73 Chevelle under mine. Its 62 inches wide across the wheel mounting face, which I think is the better place to measure. Measuring backing plates tells you if it will fit your springs, measuring the wheel mounting faces tells you where the wheels will end up under the fenders.

The 62 inch wide axle I used seems to work about perfect. The downside of the Chevelle is you have to cut the coil spring stuff off and weld on leaf spring pads. I've been driving mine five years with that Chevelle rear under it.